Johnson Propeller Sizing Questions

[peterb]

I have a 1997 175 HP Johnson Ocean Runner pushing a 20 foot, 2200 lb. center console. Currently, I have a 14.5 x 19 aluminum prop on it. <br /><br />With the current setup I can only it get it to about 4,600 RPM's (btw, the boat is going at about 47 miles per hour at this point).<br /><br />I am looking at going to a 15 x 17, SS prop. Will any Johnson or OMC, prop (rigt turning w/15 splines) do? Is there a place on the web which will tell me exactley which prop's will & won't do?<br /><br />Any help would be appreciated.

 

[walleyehed]

Re: Johnson Propeller Sizing Questions

I would look for an OMC RAKER, or VIPER.<br />The RAKER seems to be real popular on your type of set-up.

 

[Spidybot]

Re: Johnson Propeller Sizing Questions

According to Mike Guckin's estimated speed calculator at this page you should be able to do some 50-63 mph turning a 18-22" prop at 5500 rpm with a gear ratio of 1,86 - depending on hull design.<br /><br />Max. recommended rpm at wot is 5270-5750 for your motor.<br /><br />According to the same calculator 19" / 4600 rpm / 47 mph matches a boat of 3000+ lbs.<br /><br />If you can't get more than 4600 rpm, and your true weight is 2200 lbs, something else could be wrong.<br /><br />Let us know if your figures keep.